/Engine/Source/Runtime/MovieScene/Public/Evaluation/PreAnimatedState/MovieScenePreAnimatedStateStorage.h
Cause a previously cached value to always outlive any actively animating sources. This is called when a Restore State track overlaps a Keep State track. The Restore State track will initially save state using the Transient requirement, but the Keep State track may need to keep this cached state alive if it is capturingglobalstate. As such, we take the previously cached state and make it persistent.
void ForciblyPersistStorage ( [FPreAnimatedStorageIndex](API\Runtime\MovieScene\Evaluation\PreAnimatedState\FPreAnimatedStorageIndex) StorageIndex )